Fermented foods play a major role in the diet of people in Africa, where a wide variety of raw materials are fermented. Understanding the microbial populations of these products would help in the design of specific starter cultures to produce standardized and safer foods. In this study, the bacterial diversity of African fermented foods produced from several raw materials (cereals, milk, cassava, honey, palm sap, and locust beans) under different conditions (household, small commercial producers or laboratory) in 8 African countries was analysed by 16S rRNA gene amplicon sequencing during the Workshop “Analysis of the Microbiomes of Naturally Fermented Foods Training Course”. Results show that lactobacilli were less abundant in fermentations performed under laboratory conditions compared to artisanal or commercial fermentations. Excluding the samples produced under laboratory conditions, lactobacilli is one of the dominant groups in all the remaining samples. Genera within the order Lactobacillales dominated dairy, cereal and cassava fermentations. Genera within the order Lactobacillales, and genera Zymomonas and Bacillus were predominant in alcoholic beverages, whereas Bacillus and Lactobacillus were the dominant genera in the locust bean sample. The genus Zymomonas was reported for the first time in dairy, cereal, cassava and locust bean fermentations.

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The experiments reported in this research paper aimed to determine the technological properties of indigenous Lactococcus lactis strains isolated from Lait caillé, a spontaneous fermented milk, from the perspective of starter culture development. Fermentations were conducted to determine the acidification patterns. The ropy character, growth in 0.04 g/ml NaCl and citrate metabolism were additionally tested. Furthermore, the rheological properties of samples from selected strains and the impact of cold storage were evaluated. Based on the rate of acidification, the indigenous strains were divided into 2 groups depending on their fermentation time, i.e. 10–13 h (fast acidifier), and up to 72 h (slow acidifier), respectively. The physiological tests suggested that most of these strains produced exopolysaccharides but none could ferment citrate. The flow properties of the samples inoculated by the fast acidifier strains showed a time-dependent shear thinning behaviour, while their viscoelastic properties corresponded structurally to those of weak gels. Cold storage decreased the viscosity and CFU counts for most of the indigenous strains tested. This study is a step towards the definition of starter cultures for African spontaneous fermented milks such as Lait caillé.

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Lait caillé is a traditional fermented milk product in Burkina Faso. The objective of this study was to contribute to consumer acceptance of lait caillé. For this purpose, the production practices in rural and urban areas were identified through semi-structured interviews, while the perceived quality of lait caillé in urban area was investigated through a survey. Then, microbiological and physico-chemical parameters were analysed on samples from rural and urban sites. Finally, an attempt to improve the hygiene of the traditional processing was proposed by use of Lactococcus lactis and Leuconostoc mesenteroides stains as starter. These were previously isolated from traditional lait caillé. The results on the manufacturing processes revealed from the raw milk practices of spontaneous fermentation, backslopping and contact with bacterial biofilms attached to container. The survey on perceived quality indicated that traditional lait caillé possessed a niche market which could be enlarged by implementation of good manufacturing practices in the production sites. The microbiota of the end product was characterised by high loads of Enterococcus spp., Enterobacteria and Pichia spp. Fermented milks by starter cultures showed improved hygienic quality and a positive sensory appreciation. However, the use of selected strains might be followed by loss of some features of traditional lait caillé, which scientists should work to resolve.